Major FLAW discovery with Electronic throttle control with MAP sensor equipped engines

[BG1988]

if you have a broken MAP sensor or oil fouled map sensor ..
on your GM engine it will OVERRIDE the Electronic Throttle control...

really it will


Your engine will be subject to "RUN AWAY" .. this happened 2 times



2 times Engine Runaway.. Was Able to stop the run away happened from an auto stop..


looks like GM failed at the correct ECM programming, and the MAP sensor overrides the Electronic throttle control (aka gas peddle )
this is the dumbest thing ever!


The stupidest thing MAP sensor has full unrestricted control over the electronic Throttle control very smart



At this point in time it's safe to assume also MAF ECT IAT Braro sensors have full unrestricted control over the electronic Throttle control as well....according to a few websites site the MAP sensor is a backup to the MAF sensor..

I still have the old map sensor just in case... anyone wants to reproduce the issue on their svu..


I KNOW MAP sensors are a normal wear and tear item but there still should be a fail safe mode or ignore if the part has been compromised i.e faulty..

make sure you keep your map sensor clean or replace often like every 30k-40k miles esp the oil burner engines.. or IF you use an oil based air filter. I did find new clean oil on the sensor i suspect the chain shop tampered with it... were i had a oil change done at 84k miles since I had CEL after going there P0069/P0430 there was dirty oil on the engine cover were the map sensor was so the person must have tampered with it. the only person that had dirty oil on them was the person who changed it..

Since this is not a diesel engine ( turning off the engine will STOP the runaway) it means you will lose engine power items.. keep that in mind.


this can be a problem if the map sensor shorts to signal ground




Scenario

Map sensor: *yells at engine* hey i'm getting 4.5 volts to 5, you NEED to wide open the throttle NOW..

ECM: Yes sir

https://www.google.com/url?sa=t&rct...ition-sensor&usg=AOvVaw3nIpfBdLMKosNSSnPC3Sl5
Throttle Pedal Position sensor: tells ECM We have some user input please accelerate ..

ECM: TPPS what?!



ECM: Hey throttle plate Open WIDE NOW you have a full load requested by MAP sensor.


ECM says : Send more fuel and air


ECM continues to send more air and fuel causing the engine to accelerate as requested by the map sensor....




so the point is the ECU ignores the Throttle Pedal Position sensor request ... while the MAP sensor(aka back up system to the MAF) request WIDE open throttle which is agreed upon by the ECU...



the whole point of the TPPS is to be the master switch that controls all throttle response passed set idle speeds.. in gm case a mistake was made in the ECM giving the MAP sensor(possibly other sensors as well) HIGHER priority then the Throttle Pedal Position


what exactly is the point of me requesting 25-35% throttle if i'm going to get 100% throttle from another sensor requests?

 

[gpracer1]

Say what????????????????????????

 

[BG1988]

a broken map sensor can cause 100% throttle in a unrestricted fashion ...... this overrides the Safety switch
and the safety switch being the
Throttle/Accelerator Pedal Position ..



meaning the engine will accelerate without user input


user = you

engine = engine

uncontrolled acceleration = go faster without pressing gas peddle


the APP has two 5 volt signals

one leg rises as the other leg falls in voltage. using a variable resistor .. this is the fail safe.. operation. of the electronic gas peddle.

the map sensor that is broken or fouled (dirty)


OVERRIDES the fail safe operation. of the Electronic Throttle Control... causing an unrequested Wide open throttle event .

 

[gpracer1]

I have to call BS on this.
The MAP sensor is for sensing load, to adjust timing, shift points, injector pulse width, etc in harmony with other sensors like throttle position, O2 sensors and many others. It does not "command full throttle" if it fails.

It is like you are stating a fact.

 

[Rocket Man]

I also call BS. I mean, you’re the first person to experience this in a 12 year old platform? Even if it was possible, we would have heard of at least ONE accident from this happening.

 

[jeffbco]

a broken map sensor can cause 100% throttle in a unrestricted fashion ...... this overrides the Safety switch
and the safety switch being the
Throttle/Accelerator Pedal Position ..



meaning the engine will accelerate without user input


user = you

engine = engine

uncontrolled acceleration = go faster without pressing gas peddle


the APP has two 5 volt signals

one leg rises as the other leg falls in voltage. using a variable resistor .. this is the fail safe.. operation. of the electronic gas peddle.

the map sensor that is broken or fouled (dirty)


OVERRIDES the fail safe operation. of the Electronic Throttle Control... causing an unrequested Wide open throttle event .

If you truly believe this report it to the NTSB.

 

[Doubeleive]

*

 

[BG1988]

I also call BS. I mean, you’re the first person to experience this in a 12 year old platform? Even if it was possible, we would have heard of at least ONE accident from this happening.

install the MAP sensor on your SUV i'll send it to you, report the results.. from it obviously using this part would be at your own risk...


then why was the engine Revving to RED LINE 6,000 RPM by it self... did it twice from an auto stop

no other reason for that and there has not been any trouble after replacement with a brand new OEM one... even at the same intersection....


with the broken one it had :

Jerky transmission
jerky in M mode
Reverse gear refused to work correctly(jerky as well)
rhythmic Rough Idle (You could physically see the engine shaking)

Single event of
sudden power loss all these happened simultaneously

Electrical power steering Lost
brakes locked up (it came skidding to a stop from 45MPH)
ABS disabled
Stabilitrak disabled
Cluster went off...


Primary fault code P0069
Secondary fault code P0430..



remember how i said it was starting at 1500 rpm sometimes as high as 2,000 rpm

now with the replacement map sensor it's a 1100-1150 rpm from a cold start.. I took a video of it sitting over night for 14 hours

uploading it to youtube


I know everyone like to play the blame the 12V+ or High Voltage battery game

 

[Rocket Man]

install the MAP sensor on your SUV i'll send it to you, report the results.. from it obviously using this part would be at your own risk...


then why was the engine Revving to RED LINE 6,000 RPM by it self... did it twice from an auto stop

no other reason for that and there has not been any trouble after replacement with a brand new OEM one... even at the same intersection....


with the broken one it had :

Jerky transmission
jerky in M mode
Reverse gear refused to work correctly(jerky as well)
rhythmic Rough Idle (You could physically see the engine shaking)

Single event of
sudden power loss all these happened simultaneously

Electrical power steering Lost
brakes locked up (it came skidding to a stop from 45MPH)
ABS disabled
Stabilitrak disabled
Cluster went off...


Primary fault code P0069
Secondary fault code P0430..



remember how i said it was starting at 1500 rpm sometimes as high as 2,000 rpm

now with the replacement map sensor it's a 1100-1150 rpm from a cold start.. I took a video of it sitting over night for 14 hours

uploading it to youtube


I know everyone like to play the blame the 12V+ or High Voltage battery game

Sure, send it to me. Need my address?

 

[BG1988]

yea message me

your uses the clip on type correct?


you can see it's fouled with oil there was No oil when the port was probed with a q tip just a bit of dirt




I all ready had a successful drive cycle no CEL